The figures are dramatic. Forty-five per cent of people who voted “No” in the last referendum now say they would vote Conservative — up from 34% in YouGov’s survey in May. Meanwhile, unionist support for Labour dropped in the same period from 37% to 25%.

Labour’s position on independence is far from clear, and it’s hurting the party. In February, Scottish Labour leader Kezia Dugdale hinted that she might support Scottish independence, before backtracking and saying that she would vote to stay in the UK.

In the meantime, the Scottish Conservatives have positioned themselves firmly as the party of unionists and the SNP retain the support of most independence voters. Professor John Curtice, a polling expert and politics professor at the University of Strathclyde, told Business Insider that the resurgence of the Scottish independence question has left Labour “high and dry.”

“Putting the constitutional question back on the table seems to be helping the Tories and hurting Labour,” Curtice said.

“The problem for Labour is that it divides them, and their electorate. The party is split on the issue, and it isn’t comfortable talking about it. Labour is happy to talk about anything but the constitutional question,” he said.

“It’s pretty clear that the Labour party has already been shredded by the nationalists’ vote going to the SNP in the wake of the independence referendum. It now seems to be suffering from the fact that the unionist vote is now wandering off to the Tories, leaving the Labour party high and dry,” Curtice said.

“Virtually everybody who votes Tory is in favour of staying inside the union, virtually everyone who votes SNP is in favour of independence, the two parties are quite happy to talk about the constitutional question,” he added.

“Schools, hospitals, employment, anything — just don’t ask them about the constitutional question, because it’s not comfortable territory.”